Over the years, there have been a large number of proposals of various sorts of combination radiators and oil coolers. Initially, the constructions were proposed to provide a means for cooling engine lubricating oil but more recently, they tend to be employed for cooling transmission oil or hydraulic fluid.
In some cases, certain of the tubes in the radiator were segregated as by partitions to provide a separate heat exchanger to which oil would be flowed for cooling purposes. This approach is shown, for example, in U.S. Pat. No. 2,013,708 issued Sept. 10, 1935 to Bianchi et al.
In other instances, separate oil cooling cells were simply aded on to existing radiator cells by any suitable form of conventional securement. An example of this approach was found in U.S. Pat. No. 2,505,790 issued May 2, 1950 to Panthofer.
In both of the foregoing approaches, air was utilized as the cooling media for the oil, heat being transferred via tubes and fins from the oil to air passing through the heat exchanger.
Another sort of approach has also been employed. According to this approach, the oil is flowed in heat exchange relation to engine coolant and rejects heat to the coolant, which then rejects heat to the air. Examples to this approach are found in U.S. Pat. Nos. 3,116,541 issued Jan. 7, 1964 to Nickol et al and 3,265,126 issued Aug. 9, 1966 to Donaldson.
Of the two, the Nickol approach seems preferable since the oil cooling heat exchanger components are simply piggy-backed on to an existing header for a vehicular radiator although the header requires some modification to accept the oil cooler components.
Though in theory the Nickol approach works well, it is not without attendant difficulties. For one thing, the capacity of the unit is limited by structural constraints related to the header. For another, components are not particularly easy to hold in partially assembled relation during a final assembly process.
The present invention is directed to overcoming one or more of the above problems.